Battery type sensing method and device for sensing battery type

ABSTRACT

A battery type detection approach is disclosed. In one embodiment, a method of detecting a battery type can include: receiving a signal from a battery module in a portable computing device; determining if the signal is in a first state for at least a first predetermined time before transitioning to a second state; determining if the signal transitions from the second state to the first state after a second predetermined time, and identifying the battery type in response thereto; and asserting an indication of the battery type when a third predetermined time period after the transition from the second state to the first state has occurred.

FIELD OF THE INVENTION

The invention relates in general to providing power to electronicdevices, and more specifically to power supply detection and managementbased on power source type detection.

BACKGROUND

Increasing use of portable computing or electronic devices has led toincreased reliance on battery power. Devices such as cell phones,personal digital assistants (PDAs), small computers, e-mail devices,audio players, video players, etc., are often designed to use differenttypes of batteries. For example, a user may choose to purchase astandard-charge battery or a double-capacity battery for use with asingle device. Typically, a charging system is provided so that thebatteries can be re-charged from wall outlets that connect to the urbanpower grid. In many cases, a single charging system is designed tocharge different types of batteries.

It is often important to detect the type of battery being charged orused. During charging, the capacity and charge characteristics of abattery must be complied with by the charging system in order toproperly charge the battery. During use, the device using the batteryfor power may adjust its performance or other characteristics dependingupon the type of battery.

SUMMARY

A battery detection approach in accordance with embodiments of thepresent invention can be utilized to implement a power management regimesuitable for each type of battery. Further, a single wire interfacebetween a battery subsystem or module and an embedded controller in aportable computing device can be used to determine the battery type. Inaddition, other safeguards can be implemented for cases where anunapproved battery type has been attached to the portable computingdevice.

In one embodiment, a method of detecting a battery type can include:receiving a signal from a battery module in a portable computing device;determining if the signal is in a first state for at least a firstpredetermined time before transitioning to a second state; determiningif the signal transitions from the second state to the first state aftera second predetermined time, and identifying the battery type inresponse thereto; and asserting an indication of the battery type when athird predetermined time period after the transition from the secondstate to the first state has occurred.

In one embodiment, a method of controlling a battery module in aportable computing device can include: determining a battery type usinga signal received from the battery module; allowing charging of thebattery module at a first rate when a first battery type has beendetected; allowing charging of the battery module at a second rate whena second battery type has been detected; and adjusting access to thebattery module when neither the first nor the second battery types havebeen detected.

In one embodiment, a portable computing device can include: one or moreprocessors; and logic encoded in one or more tangible media forexecution by the one or more processors, and when executed operable to:receive a signal from a battery module; determine if the signal is in afirst state for at least a first predetermined time before transitioningto a second state; determine if the signal transitions from the secondstate to the first state after a second predetermined time, and identifya battery type in response thereto; and assert an indication of thebattery type when a third predetermined time period after the transitionfrom the second state to the first state has occurred.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example portable computing device arrangement inaccordance with embodiments of the present invention.

FIG. 2 shows an example battery module structure in accordance withembodiments of the present invention.

FIG. 3 shows an example waveform for battery type detection inaccordance with embodiments of the present invention.

FIG. 4 shows a flow diagram of a first example method of detecting abattery type in accordance with embodiments of the present invention.

FIG. 5 illustrates a flow diagram of an example method of controlling abattery module based on battery type in accordance with embodiments ofthe present invention.

FIG. 6 illustrates a flow diagram of a second example method ofdetecting a battery type in accordance with embodiments of the presentinvention.

DETAILED DESCRIPTION

Electronic devices and batteries typically interface or provideinformation flow, such as: alarm flags, over/under-voltagenotifications, over/under-current notifications, average current flow,instantaneous current flow, estimates of total charge left in thebattery, numerical integration of current flow measurements, cycletimes, total cycles expended, temperature measurements, fuel gauges,safety circuit status, as well as charge/discharge device status, forexample.

Referring now to FIG. 1, an example portable computing devicearrangement in accordance with embodiments of the present invention isindicated by the general reference character 100. Portable computingdevice 102 can include embedded controller 104, battery subsystem 106,user interface control 108, and display 110, for example. Althoughbattery subsystem 106 is described primarily with respect to batteries,it can include any other suitable type of energy-providing mechanisms,such as capacitors and/or any suitable combination of capacitors andbatteries. Also, some features described herein may be adaptable to anyother type of power source, such as where an external battery is used(e.g., a device obtaining power from a vehicle's battery), or where astandard line power is used (e.g., alternating current residential orbusiness infrastructure power). Further, battery subsystems or modulescan include or be associated with unique identifiers (IDs), ornonvolatile storage elements (e.g., electrically erasable programmableread-only memory (EEPROM)) to save power management preferences.

In particular embodiments, a single wire interface 112 can be utilizedbetween embedded controller 104 and battery subsystem 106 in order todetermine a battery type. In this fashion, a battery can communicatewith portable computing device 102 via embedded controller 104. Further,communication can occur within battery subsystem 106 (e.g., betweencomponents or chips therein to regulate power consumption, charging,report on status, etc.). For example, one wire interface 112 can beutilized to determine if battery subsystem 106 contains a singlecapacity type battery, or a double capacity type battery. Of course,other battery types and/or interfaces can also be accommodated inparticular embodiments.

Referring now to FIG. 2, an example battery module structure inaccordance with embodiments of the present invention is shown andindicated by the general reference character 200. Embedded controller202 can interface with battery module 204 via one wire interface 212.Battery module 204 can include battery charge/discharge control 206, aswell as battery portions 208-0 and 208-1. In particular embodiments,detections as to whether both battery portions are filled, or othersuitable battery arrangements, can be found using embedded controller202 via interface 212, and then utilized to control battery chargesupply 210. Battery charge supply 210 can include a plug for AC powercoupled to a DC adapter, or any other suitable approach for providingcharge to battery module 204.

For example, two different types of batteries may be accommodated in aparticular portable computing device, and one may be charged at twice(e.g., a double capacity battery type) the charge rate as the other(e.g., a single capacity battery type). In one example, two singlebattery portions (e.g., 208-0 and 208-1) can be arranged in parallel,such that twice the current can be applied or allowed for charging(e.g., via a battery charge supply 210) when both battery portions areoccupied (e.g., detected as a certain battery type), as opposed to onlyone such portion being occupied (e.g., detected as a different batterytype).

Referring now to FIG. 3, an example waveform for battery type detectionin accordance with embodiments of the present invention is shown andindicated by the general reference character 300. For example, thebattery module interface signal can be one wire interface 212, as shownabove in FIG. 2. In FIG. 3, signal portion 302 may representcommunication substantially within or related to the battery subsystem(e.g., may not be related to a battery type detection protocol), and maybe characterized by multiple signal transitions (e.g., logic high/lowlevel transitions).

Signal portion 304 may indicate that this “battery talk” (e.g., signalportion 302) is ending, such that the bus or one wire interface can beutilized by the embedded controller. For example, signal portion 304 maybe characterized by maintaining a high level for at least 1 ms. Ofcourse, any other suitable predetermined time period (e.g., from about0.75 ms to about 1.25 ms, or about 0.5 ms to about 1.5 ms) or voltagelevel (e.g., low instead of high, or some intermediate level) on the onewire interface can also be used in particular embodiments.

Next, signal portion 306 including a low level portion, can be sampled apredetermined time (e.g., during sampling window 308) after the high tolow transition (e.g., bordering signal portions 304 and 306). Forexample, the predetermined time for sampling may be within about 1.5 msto about 2.5 ms. Of course, any other suitable predetermined time period(e.g., from about 1.25 ms to about 2.75 ms, or about 1.0 ms to about 3.0ms) on the one wire interface can also be used in particularembodiments. In particular embodiments, if the signal has remained lowfor at least 1 ms (or some other suitable time period prior to enteringthe sampling window), sampling window 308 may be utilized to determinewhen the signal goes high to identify the battery as a first (e.g.,single capacity) or a second (e.g., double capacity) type. Such abattery type indication may be asserted by the embedded controller afteranother time period (e.g., portion 310) when the signal is in a highlevel. For example, portion 310 may extend for at least 64 ms, or anyother suitable predetermined time (e.g., from about 50 ms to about 80ms).

Further, if a user of the portable computing device disconnects thebattery and the one wire interface goes low for some extended interval,then the protocol detection program can be reset by the embeddedcontroller. Also, the battery module may communicate within itselfperiodically, such as shown in signal portion 302. For example, thebattery module may interrogate itself (e.g., a heartbeat test)periodically (e.g., every 6 seconds) to ensure appropriate connections,battery charge levels, or the like. In particular embodiments, thebattery module may also provide indications conforming to apredetermined protocol as described herein to the embedded controllerfor battery type determination.

Referring now to FIG. 4, a flow diagram of a first example method ofdetecting a battery type in accordance with embodiments of the presentinvention is shown and indicated by the general reference character 400.A second example battery type detection method will be discussed belowwith reference to FIG. 6. In FIG. 4, the flow can begin (402), and asignal may be received from a battery module, and may be received in anembedded controller of a portable computing device (404). If the signalis high for at least 1 ms before going low (406), the signal may besampled for a low to high transition at a predetermined time (e.g., fromabout 1.5 to about 2.5 ms) after the high to low signal transition(408). If the signal is not detected as high for at least 1 ms (406),the signal can be monitored (404), and may be within a battery talksignal portion (e.g., 302 of FIG. 3), or some other portion.

Once the signal has been sampled for a low to high transition (408), ifthe signal is now high at the sample point (410), the battery module maybe designated as a first type (412). Alternatively, if the signal is notyet high at the sample point (410), the battery module may be designatedas a second type (414). If either the first or the second battery typeis so detected, a battery type indication may then be asserted if thesignal remains high for at least 64 ms (416), and the flow can complete(418). In this fashion, a battery type can be detected using a singlewire interface, where the battery module may drive the signal conformingto a particular predetermined protocol.

In addition, while particular predetermined time periods, samplingwindows, and voltage levels (e.g., logic high or low levels) aredescribed herein with respect to particular examples, any suitableapproaches may also be used. For example, small-swing voltages,differential signaling, and/or current-based control can also be usedfor battery type determination using an interface between the batterymodule and the embedded controller. Further, timing aspects, such aspredetermined time periods and sampling windows, may be varied inparticular embodiments.

Referring now to FIG. 5, a flow diagram of an example method ofcontrolling a battery module based on battery type in accordance withembodiments of the present invention is shown and indicated by thegeneral reference character 500. The flow can begin (502), and a batterytype may be determined using a signal received from a battery module(504). For example, this determination can be made using the flow asshown above in FIG. 4. In FIG. 5, if the first battery type has beendetected (506), charging of the battery module may be allowed at a firstrate (508), and the flow can complete (516).

If the first battery type has not been detected (506), but the secondbattery type has been detected (510), charging of the battery module maybe allowed at a second rate (512), and the flow can complete (516).However, if neither the first type (506), or the second type (510) ofbattery is detected, usage or battery module access may be restricted,or charging may simply be allowed at a first “safe” rate (514), thuscompleting the flow (516). For example, such usage restriction canprevent unauthorized third-party battery add-ons, and in such a case,the battery may not effectively work with the portable computing device.Other options include suppressing certain functions, reducing devicespeed, increasing a discharge rate of the battery, etc., for suchunauthorized batteries that are detected. For the option of allowingcharging at a first safe rate (514), the battery module can be treatedas if the first battery type was in fact detected.

Referring now to FIG. 6, a flow diagram of a second example method ofdetecting a battery type in accordance with embodiments of the presentinvention is shown and indicated by the general reference character 600.The flow can begin (602), and once the signal is detected high for atleast 1 ms (604), the signal can be tested to determine if it is now low(606). Once the signal is sampled as low (606), a counter can be started(608). Such a counter can be used to determine how long the signalremains low before transitioning high. As discussed above, this lowportion range can typically be from about 1.5 ms to about 2.5 ms in oneexample. The counter can continue counting until the signal transitionshigh (610), thus stopping the counter (612).

At this point, the low portion time range can be ascertained from thecounter result. If the counter result is less than about 1.5 ms (614),the battery can be characterized as a first type (616), and the flow cancomplete (624). However, if the counter is greater than 1.5 ms (614),but less than about 2.5 ms (618), the battery can be characterized as asecond type (620), and the flow can complete (624). If neither the firstnor the second type is explicitly determined, the battery modulecharging allowance can be set at a first type safe rate (622), thuscompleting the flow (624). Of course, while only two battery typedeterminations have been shown in this particular example, any number ofbattery types can be accommodated in specific embodiments. For example,counter results indicating ranges from about 2.5 ms to about 3.5 ms, andfrom about 3.5 ms to about 4.5 ms, and so on, can be utilized todetermine any number of battery module types in specific embodiments.

Although particular embodiments of the invention have been described,variations of such embodiments are possible and are within the scope ofthe invention. For example, although specific battery types andprotocols have been described, other types of batteries, numbers ofallowable battery types, and/or protocols, can be accommodated inaccordance with embodiments of the present invention. Also, applicationsother than portable computing devices or the like can also beaccommodated in accordance with particular embodiments. Embodiments ofthe invention can operate among any one or more processes or entitiesincluding users, devices, functional systems, and/or combinations ofhardware and software.

Any suitable programming language can be used to implement thefunctionality of the present invention including C, C++, Java, assemblylanguage, etc. Different programming techniques can be employed such asprocedural or object oriented. The routines can execute on a singleprocessing device or multiple processors. Although the steps, operationsor computations may be presented in a specific order, this order may bechanged in different embodiments unless otherwise specified. In someembodiments, multiple steps shown as sequential in this specificationcan be performed at the same time. The sequence of operations describedherein can be interrupted, suspended, or otherwise controlled by anotherprocess, such as an operating system, kernel, etc. The routines canoperate in an operating system environment or as stand-alone routinesoccupying all, or a substantial part, of the system processing. Thefunctions may be performed in hardware, software or a combination ofboth.

In the description herein, numerous specific details are provided, suchas examples of components and/or methods, to provide a thoroughunderstanding of embodiments of the present invention. One skilled inthe relevant art will recognize, however, that an embodiment of theinvention can be practiced without one or more of the specific details,or with other apparatus, systems, assemblies, methods, components,materials, parts, and/or the like. In other instances, well-knownstructures, materials, or operations are not specifically shown ordescribed in detail to avoid obscuring aspects of embodiments of thepresent invention.

A “computer-readable medium” for purposes of embodiments of the presentinvention may be any medium that can contain, store, communicate,propagate, or transport the program for use by or in connection with theinstruction execution system, apparatus, system or device. The computerreadable medium can be, by way of example only but not by limitation, anelectronic, magnetic, optical, electromagnetic, infrared, orsemiconductor system, apparatus, system, device, propagation medium, orcomputer memory.

A “processor” or “process” includes any human, hardware and/or softwaresystem, mechanism or component that processes data, signals or otherinformation. A processor can include a system with a general-purposecentral processing unit, multiple processing units, dedicated circuitryfor achieving functionality, or other systems. Processing need not belimited to a geographic location, or have temporal limitations.Functions and parts of functions described herein can be achieved bydevices in different places and operating at different times. Forexample, a processor can perform its functions in “real time,”“offline,” in a “batch mode,” etc. Parallel, distributed or otherprocessing approaches can be used.

Reference throughout this specification to “one embodiment”, “anembodiment”, “a particular embodiment,” or “a specific embodiment” meansthat a particular feature, structure, or characteristic described inconnection with the embodiment is included in at least one embodiment ofthe present invention and not necessarily in all embodiments. Thus,respective appearances of the phrases “in one embodiment”, “in anembodiment”, or “in a specific embodiment” in various places throughoutthis specification are not necessarily referring to the same embodiment.Furthermore, the particular features, structures, or characteristics ofany specific embodiment of the present invention may be combined in anysuitable manner with one or more other embodiments. It is to beunderstood that other variations and modifications of the embodiments ofthe present invention described and illustrated herein are possible inlight of the teachings herein and are to be considered as part of thespirit and scope of the present invention.

Embodiments of the invention may be implemented by using a programmedgeneral purpose digital computer, by using application specificintegrated circuits, programmable logic devices, field programmable gatearrays, optical, chemical, biological, quantum or nanoengineeredsystems, components and mechanisms may be used. In general, thefunctions of the present invention can be achieved by any means as isknown in the art. For example, distributed, networked systems,components and/or circuits can be used. Communication, or transfer, ofdata may be wired, wireless, or by any other means.

It will also be appreciated that one or more of the elements depicted inthe drawings/figures can also be implemented in a more separated orintegrated manner, or even removed or rendered as inoperable in certaincases, as is useful in accordance with a particular application. It isalso within the spirit and scope of the present invention to implement aprogram or code that can be stored in a machine-readable medium topermit a computer to perform any of the methods described above.

Additionally, any signal arrows in the drawings/Figures should beconsidered only as exemplary, and not limiting, unless otherwisespecifically noted. Furthermore, the term “or” as used herein isgenerally intended to mean “and/or” unless otherwise indicated.Combinations of components or steps will also be considered as beingnoted, where terminology is foreseen as rendering the ability toseparate or combine is unclear.

As used in the description herein and throughout the claims that follow,“a”, “an”, and “the” includes plural references unless the contextclearly dictates otherwise. Also, as used in the description herein andthroughout the claims that follow, the meaning of “in” includes “in” and“on” unless the context clearly dictates otherwise.

The foregoing description of illustrated embodiments of the presentinvention, including what is described in the Abstract, is not intendedto be exhaustive or to limit the invention to the precise formsdisclosed herein. While specific embodiments of, and examples for, theinvention are described herein for illustrative purposes only, variousequivalent modifications are possible within the spirit and scope of thepresent invention, as those skilled in the relevant art will recognizeand appreciate. As indicated, these modifications may be made to thepresent invention in light of the foregoing description of illustratedembodiments of the present invention and are to be included within thespirit and scope of the present invention.

Thus, while the present invention has been described herein withreference to particular embodiments thereof, a latitude of modification,various changes and substitutions are intended in the foregoingdisclosures, and it will be appreciated that in some instances somefeatures of embodiments of the invention will be employed without acorresponding use of other features without departing from the scope andspirit of the invention as set forth. Therefore, many modifications maybe made to adapt a particular situation or material to the essentialscope and spirit of the present invention. It is intended that theinvention not be limited to the particular terms used in followingclaims and/or to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include any and all embodiments and equivalents falling within thescope of the appended claims.

Thus, the scope of the invention is to be determined solely by theappended claims.

1. A method of detecting a battery type, comprising: receiving a signalof a waveform that has high and low logic levels and transitions betweenthe high and low logic levels from a battery module in a portablecomputing device; determining if the signal is in a first state which isone of the high and low logic levels for at least a first predeterminedtime before transitioning to a second state which is the other of thehigh and low logic levels; determining if the signal transitions fromthe second state to the first state after a second predetermined time,and identifying the battery type in response thereto; and asserting anindication of the battery type when a third predetermined time periodafter the transition from the second state to the first state hasoccurred.
 2. The method of claim 1, wherein the receiving the signalcomprises using a one wire interface between the battery module and anembedded controller.
 3. The method of claim 1, wherein the first statecomprises a logic high level.
 4. The method of claim 1, wherein thesecond state comprises a logic low level.
 5. The method of claim 1,wherein the first predetermined time comprises about 1 ms.
 6. The methodof claim 1, wherein the second predetermined time comprises from about1.5 ms to about 2.5 ms.
 7. The method of claim 1, wherein the thirdpredetermined time comprises about 64 ms.
 8. The method of claim 1,wherein the identifying the battery type in response to the signaltransition determination comprises identifying a first battery type ifthe signal has transitioned prior to a sampling at the secondpredetermined time.
 9. The method of claim 1, wherein the identifyingthe battery type in response to the signal transition determinationcomprises identifying a second battery type if the signal has not yettransitioned prior to a sampling at the second predetermined time. 10.The method of claim 1, wherein the asserting the indication of thebattery type comprises controlling an allowable charge rate of thebattery module.
 11. A method of controlling a battery module in aportable computing device, the method comprising: receiving a signalfrom the battery module of a waveform that has high and low logic levelsand transitions between the high and low logic levels from a batterymodule in a portable computing device; determining if the signal is in afirst state which is one of the high and low logic levels for at least afirst predetermined time before transitioning to a second state which isthe other of the high and low logic levels; determining if the signaltransitions from the second state to the first state after a secondpredetermined time, and identifying the battery type in responsethereto; determining a battery type using a signal received from thebattery module; allowing charging of the battery module at a first ratewhen a first battery type has been detected; allowing charging of thebattery module at a second rate when a second battery type has beendetected; and adjusting access to the battery module when neither thefirst nor the second battery types have been detected.
 12. The method ofclaim 11, wherein the determining the battery type comprises sampling astate of the signal at predetermined times.
 13. The method of claim 11,wherein the first rate is about half the second rate.
 14. The method ofclaim 11, wherein the allowing charging of the battery module at thefirst rate comprises disabling a portion of a charge path to the batterymodule.
 15. The method of claim 11, wherein the allowing charging of thebattery module at the second rate comprises enabling a full charge pathto the battery module.
 16. The method of claim 11, wherein the adjustingaccess to the battery module comprises substantially reducing chargeavailable to be drawn from the battery module.
 17. The method of claim11, wherein the adjusting access to the battery module comprisesdisabling access to charge from the battery module.
 18. A portablecomputing device, comprising: one or more processors; and logic encodedin one or more non-transitory tangible media for execution by the one ormore processors, and when executed operable to: receive a signal of awaveform that has high and low logic levels and transitions between thehigh and low logic levels from a battery module; determine if the signalis in a first state which is one of the high and low logic levels for atleast a first predetermined time before transitioning to a second statewhich is the other of the high and low logic levels; determine if thesignal transitions from the second state to the first state after asecond predetermined time, and identify a battery type in responsethereto; and assert an indication of the battery type when a thirdpredetermined time period after the transition from the second state tothe first state has occurred.
 19. The portable computing device of claim18, wherein the one or more processors comprise an embedded controller.20. The portable computing device of claim 19, wherein the signal isreceived using a one wire interface between the battery module and theembedded controller.
 21. The method of claim 1, wherein the step ofidentifying the battery type further comprises determining a number ofbattery portions that are occupied in a battery module.
 22. The methodof claim 1, further comprising: in response to the asserted indicationof the battery type, beginning charging of the battery module in theportable device according to the indicated battery type.
 23. Theportable computing device of claim 19, further comprising logic encodedin one or more non-transitory tangible media for execution by the one ormore processors, and when executed operable to: begin charging thebattery module in the portable device in response to the assertedindication of the battery type.
 24. A method, comprising: prior toallowing a battery to be charged, receiving a signal of a waveform thathas high and low logic levels and transitions between the high and lowlogic levels from a battery module in a portable computing device;determining if the signal is in a first state which is one of the highand low logic levels for at least a first predetermined time beforetransitioning to a second state which is the other of the high and lowlogic levels; determining if the signal transitions from the secondstate to the first state after a second predetermined time, andidentifying the battery type in response thereto; and asserting anindication of the battery type when a third predetermined time periodafter the transition from the second state to the first state hasoccurred.